Full Depth Reclamation Fly Ash Stabilization MERRILL AIRPORT & LANGLADE COUNTY AIRPORT (Antigo)
Pulverize Asphaltic Pavement and Base Course Full Depth Reclamation – aka – Cold In-place Recycling [CIR] � A reclamation technique in which the full flexible pavement section and a � predetermined portion of the underlying materials are uniformly crushed, pulverized, or blended, resulting in a stabilized base course; Used to fix irregular cross sections, reflective/alligator cracking, heavy � pothole patching, severe rutting/shoving, and insufficient base strength. Substantial savings can be realized while meeting environmental goals. Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 2
Typical Candidates for Pulverize Asphaltic Pavement and Base Course Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 3
Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 4
Overview � Cold In-place Recycling [CIR] � Proportioned mixture • Fly Ash – 10 to 12% by weight (110# per SY) • Aggregate (Reclaimed Asphalt Base) • Water – 9 to 12 % typical for optimum density � Mixed in-place and compacted (12” depth for sub-grade stabilizing; 8” depth for CIR) � Produces a strong and durable pavement base course (300 - 450 psi) for flexible pavements. � Typical cost ranges from $3.50 to $4.00 per SY complete – ready to pave. Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 5
Fly Ash Storage Hopper (Silo) to Tanker Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 6
Problems Solved by Recycling HMA Pavement & Base � Bridges poor sub-grades and underlying soils. � Provides medium to improve drainage. � Provides a transitional load-bearing layer between the pavement layer and the underlying wet and unstable sub-grade soil. Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 7
Base Stabilization – “The Process” � Cold-in-place recycling begins with pulverizing the existing asphalt pavement and underlying base course. Top – Bomag [Light duty] � Bottom – Wirtgen [Heavy duty] � Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 8
Base Stabilization – “The Process” Pulverized / blended material � is then re-compacted and graded to proper crown and cross slope. In essence, a new base is � created that can either serve as a stable foundation for a new asphalt surface. Top – Pulverize, re-grade & � compact. Bottom – Evidence of soft & � unstable sub-grade Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 9
Base Stabilization – “The Process” Deliver Fly Ash and transfer to � Vane Feeder Spread Fly Ash uniformly on the � newly prepared recycled base. Vane feeder distributors controls � concentration of ash and controls dust. Fly Ash is very fine and tends to � blow about when windy or disturbed Top – Tanker truck transfer to vane � feeder. Bottom - Spreading Fly Ash. � Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 0
Base Stabilization – “The Process” � Reclaimer / Pulverizer follows water truck, mixing: � Fly Ash, � Recycled Base, and � Water – injected directly into the pulverizer � Water is needed to begin the hydration process similar to cement. � Moisture content is critical to performance Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 1
Base Stabilization – “The Process” Water injected directly into the pulverizer Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 2
Base Stabilization – “The Process” � Immediately behind the mixing process, a vibratory pad-foot roller follows to produce the desired density. � The compacted material is then graded to final profile, crown and cross slope. Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 3
Base Stabilization – “The Process” � Surface is again compacted and sealed using a smooth drum or pneumatic roller � Occasionally, the surface is re-wetted to ensure completion of the hydration process � Hydration will be complete in 3-4 hours. � Monitoring moisture content is critical Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 4
Base Stabilization – “The Process” � The new stabilized base is now ready for paving. Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 5
Base Stabilization – “The Process” Bottom Asphalt Layer – 106% payment based on densities � Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 6
Base Stabilization – “The Process” � Langlade County Airport Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 7
Base Stabilization – “The Process” Estimated Costs – Cold In-place Recycling � (Merrill Airport) Fly Ash application 1. Applied at a rate of 120 lb./SY 12” average application depth. � Very soft areas treated w/ heavier application rate or deeper. � COST - $68,000 � EBS [Excavation Below Sub-grade] 2. 18” deep. � Replace EBS with CABC. � COST - $132,000 � Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 8
Base Stabilization – “The Process” Estimated Costs – Base Stabilization � (Langlade Co. Airport) Fly Ash application 1. Applied at a rate of 110 lb./SY 12” average application depth. � Very soft areas treated w/ heavier application rate or deeper. � COST - $58,000 � EBS [Excavation Below Sub-grade] 2. 2-feet deep. � Replace EBS w/ 1.5 ft. borrow material and 0.5’ ft CABC. � COST - $120,000 � Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 1 9
Thank You Questions? Lafarge graphic standards for slide shows / Corporate Communications Department June 2000 2 0
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